Language and the brain (Part One)

“Here is this three-pound mass of jelly you can hold in the palm of your hand, and it can contemplate the vastness of interstellar space. It can contemplate the meaning of infinity and it can contemplate itself contemplating on the meaning of infinity.”

VS Ramachandran

In this, which I hope is the first in a series of articles attempting to shed some light on the “how”, “when”, “what”, “why” and “who” of language, we will be going under the hood of the organ that is mainly responsible for human communication, without which the mouth, the tongue, the throat, the eyes and the ears would be limited to their basic functions.

The identification of the areas of the brain that are involved in language has not been straightforward, nor has it led to definitive answers, despite advancements in technology that allow us unprecedented access to the workings of the brain.

The two names that always come up in any discussion of the interconnection between language and the brain are those of the French neurosurgeon Paul Broca and of the German neurologist Carl Wernicke. They were the first to associate certain regions of the brain with the production and understanding of spoken language. These regions bear the scientists’ names and we will have the opportunity to return to them when we speak of all the things that can go wrong with the brain and, by extension, with the language it produces.

A close up of a map

Description generated with high confidence

Based on the work of these pioneers, in the 1960s and 1970s the American neurologist Norman Geschwind produced the first model of the general organization of the language functions in the brain. The Wernicke-Geschwind Model posits that the perception, comprehension, production, etc. of language is managed by a distinct functional module in the brain, and that each of these modules is linked to the others by a very specific set of serial connections. When we hear a word spoken, the brain’s primary auditory cortex processes this auditory signal and then sends it on to the neighbouring Wernicke’s area. Wernicke’s area connects this signal with the representation of a word stored in our memory, thus enabling us to retrieve the meaning of that word. When we read a word, on the other hand, the information is perceived first by our visual cortex, which then transfers it to the angular gyrus, from which it is sent on to Wernicke’s area.

Whether we hear someone else speak a word or we read the word ourselves, it is the mental lexicon in Wernicke’s area that recognizes this word and correctly interprets it according to the context. For us then to pronounce this word, this information must be transmitted to a destination in Broca’s area, which plans the pronunciation process. Lastly, this information is routed to the motor cortex, which controls the muscles that we use to pronounce the word[1].

Modern diagnostic techniques, such as PET[2] scans and fMRI[3], appear to corroborate these findings, although the mysteries of language production and understanding in the brain are far from being fully brought to light.


[1] Information retrieved from http://thebrain.mcgill.ca/flash/d/d_10/d_10_cr/d_10_cr_lan/d_10_cr_lan.html

[2] Positron Emission Tomography

[3] Functional Magnetic Resonance Imaging

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